1. Field of the Invention
The present invention relates to an electrical connector, and particularly to an electrical connector having a plurality of ground buses for enhancing signal transmission, especially in high frequency.
2. Prior Art of the Invention
U.S. Pat. No. 5,813,871 discloses an electrical connector assembly for interconnecting two circuit boards which transmit relatively high frequency signals. The electrical connector assembly includes a receptacle connector and a mating plug connector. The plug connector includes a central elongated ground plate which has a plurality of leads along its length for engaging with a circuit board. The leads extend from opposite sides of the ground plate at equal intervals.
The receptacle connector includes a base and a plurality of shield plates. The base has a cavity defined therein for receiving a mating portion of the plug connector and a central portion extending into the cavity with a slot defined therein extending lengthwise therethrough. When the plug connector and the receptacle connector are fully mated, the elongated ground plate of the plug connector extends substantially into the slot and is in electrical engagement with each of the shield plates of the receptacle connector. This provides a relatively short ground path from a first circuit board attached to the receptacle connector to a second circuit board attached to the plug connector, thereby significantly reducing crosstalk between two adjacent signal contacts of the electrical connector assembly.
However, the prior art discloses only a single ground plate within the plug connector, where the coplanarity of the ground plate is critical in the electrical connection with the shield plates of the receptacle connector. Accordingly, the electrical ground path will be negatively influenced because the coplanarity demand of the single ground plate is difficult to meet during manufacturing or due to other reasons which may result in some connections not being terminated. U.S. Pat. No. 6,338,635 having one common inventor and the same assigned with the instant invention, discloses some approach.
A first object of the present invention is to provide an electrical connector having a plurality of ground buses which are arranged as close to the signal terminals as possible for providing reliable shielding.
A second object of the present invention is to provide an electrical connector having a plurality of ground buses which can be used for either grounding or power transmission.
In order to achieve the above mentioned objects, an electrical connector to be mounted on a printed circuit board in accordance with the present invention comprises an insulative housing having a bottom wall, a pair of side walls and a pair of end walls which cooperatively define a receiving cavity. A plurality of passageways are defined in the bottom wall and communicating with the receiving cavity. A plurality of terminals are retained in corresponding passageways of the insulative housing. At least one ground bus module is received in the receiving cavity and each includes a non-conductive body having an inner surface and an opposite outer surface on which the mating beams of the terminals are positioned. A plurality of ground buses are integrally and embededly molded with the inner surface of the non-conductive body for mating with corresponding grounding members of the complementary connector, thereby being close enough to corresponding terminals to therefore provide effective ground reference.